Afghanistan's minister of mining today claimed the war-torn country holds untapped minerals worth more than $3 trillion as he prepares to travel to London next week to lure international firms to invest in the region.

The minister, Wahidullah Shahrani said an estimate last week by the US defence department that the country's massive deposits of copper, iron, gold and lithium could be worth $1 trillion was far too conservative.

Next week Shahrani will host an investment roadshow aiming to generate investor interest in areas including Hajigak, in Afghanistan's central highlands, which has a massive iron deposit.

However, if the minister wants to appeal to blue-chip giants such as BHP Billiton, Rio Tinto and Xstrata, he is likely to be disappointed.

One industry insider agreed Afghanistan was a "very prospective region" but said any moneymaking opportunities were "a generation away".

"The health and safety concerns mean mining there is not an option for us at the moment — the risk is just too great," she said.

The development opportunity may instead appeal to Chinese miners, who are already working in the country. In 2007, Afghanistan awarded a massive copper contract to a Chinese consortium to work in the Aynak region, south of Kabul.

Indian firms are also expected to come to London to meet the Afghan officials.